Successful therapy for shock depends upon correction of the basic factor(s) responsible for shock before sequelae develop which result in irreversibility. Canine studies have strongly implicated proteolytic enzymes in the development of irreversible shock. Studies of prolonged shock in the subhuman primate demonstrate late changes consistent with proteolysis. The primary purpose of this project is to demonstrate the presence of proteolytic enzymes in the subhuman primate. The concept of I125 labeled hormone incubation with "shock plasma" is an unique method to establish enzymatic activity while identifying those hormones especially sensitive to degradation in the shock state. Administration of proteolytic enzymes to an ex vivo hepatorenal perfusion model will then provide a closely controlled system for analysis of both direct hemodynamic and metabolic effects and indirect effects due to interaction between organs. Respiratory support during prolonged shock in addition to improving oxygenation and preserving energy expenditure provides benefits not related to ventilation. Evaluation of changes noted with prolonged shock under varying conditions of respiratory support provides information concerning non-ventilatory pulmonary responsibilities during shock.